Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Storms and Convective Discussion - 20th April 2019 onwards


Supacell

Recommended Posts

Posted
  • Location: Bexley (home), C London (work)
  • Weather Preferences: Thunderstorms
  • Location: Bexley (home), C London (work)

Within around an hour now of anticipated initiation . The extent of development and its initial direction of travel will greatly assist with what we can expect later.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Bedfordshire
  • Weather Preferences: Thunderstorms, plumes, snow, severe weather
  • Location: Bedfordshire

I'm gonna keep an eye out for those small showers developing in north Hampshire.

Link to comment
Share on other sites

Posted
  • Location: Bexley (home), C London (work)
  • Weather Preferences: Thunderstorms
  • Location: Bexley (home), C London (work)
1 minute ago, LightningLover said:

Hatch stops at Eastbourne; I'm in Bexhill...

Close enough!

If you’re going to be anywhere vis-à-vis “the hatch” Id rather be east of it! 

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Beckenham, Kent, UK
  • Weather Preferences: Thunderstorms, snow, strong winds
  • Location: Beckenham, Kent, UK
46 minutes ago, Harry said:

In addition to Nick F’s forecast, PJB (UKWW) has updated his thoughts for this evening:

 

Update 18:00 BST 

No Changes to earlier Risk Zones but increased to 90% Risk and added a zone of most impact. 


Detail 

Afternoon Temperatures over France in the Paris region have reached around 30-31C, The air lifted here too dry and subsided to produce significant convection. The trajectories at 950mbs / 925mbs take this very warm air westwards towards an area of 925mb confluence to an area to the South of the Cherbourg Peninsula. This area of enhanced confluence just aloft will be enough to initiate convection in a few hours time. At the present aloft there is an area of decreasing positive earth vorticity advection moving NNE from a SSW direction across extreme Northern France and England and Wales. This largely responsible for the decreasing mid level ascent and the clouds thinning and breaking. To the South over Biscay an area of increasing Positive earth vorticity advection is located between 47.5N and 42N and is responsible for the increase in convection over the Bay of Biscay. There is also an area of shear vorticity in the flow and over N Spain a shear axis. During the day the plume of high theta -w has advected northwards across France and the storms will fire in the zone of greatest 850mb moisture and heat for the air rising within the confluence zone to the South of Cherbourg. So we have Southerly flow at 850mbs, easterly flow at 925mbs meeting Northerly flow at 950mbs, and a cooling and increasing spinning environment aloft above 700mbs. This combination of low level confluence, 850mb moisture and cooling and increasingly active kinematic environment aloft will allow for storms to grow rapidly once they form. The 12Z Models are in good agreement in taking the multi-cells to the NE over English Channel - routed to nr 900-920mbs with the perfect 850mb airflow to sustain inflow and to grow daughter cells on the south and south east of the growing organised storm complex. As the storms grow the divergence aloft from the right entrance to a SW Jet stream aloft over Biscay and the increasing positive earth vorticity will allow for outflow to be taken North east wards away from the storms and into another small scale jet over the Central North Sea. Therefore the atmospheric chimney is effectively setting up very nicely for some very active cells indeed to move NE. Supercells are possible as the system grows and there is the added low level confluence to add to further storms which develop over and up the M11 towards the Wash during the latter part of the night, due to some further increase in the low level confluence and a greater amount of upper level divergence and a slight increase in the upper level kinematics over this region during the 03Z to 06Z on Tuesday. Area should be considered to have increase low level helicity and possible super cellular tornado possibilities. (PROB 20-25%) 

Very high rainfall rates of 80/150mm/h are likely as the zone moves North . The French AROME Model somewhat further east with its precipitation field. However there is good agreement from the Dutch Hirlam, ICON, ARPEGE and UKMET 2KM in the zone from Sussex and East Hants, up across Surrey and across Central London and then up the M11 towards Cambridge and the Wash. Frequent Lightning, Flooding and Hail are possible. The small but not negligible risk of Tornado activity later in the period is mentioned above 

Disruption and delays to the Travel Network are extremely likely as well as the power network.  

OVERALL RISK ASSESSMENT IS NOW RAISED TO 90% for the areas mentioned above and in the graphic.

Attached thumbnail(s)

F54928A9-29C8-4DE6-BB4B-7EEF64D0C5E0.png

I’m right in the firing line for that! Hope I’m in for a treat!

Link to comment
Share on other sites

Posted
  • Location: Benson, Oxfordshire
  • Location: Benson, Oxfordshire

Interesting developments to my south.  A line of convection is forming. Whether it electrified or not remains to be seen, but it's looking very threatening outside 

Link to comment
Share on other sites

Posted
  • Location: Gillingham, Kent
  • Weather Preferences: Snow, Thunderstorms,
  • Location: Gillingham, Kent

I'm just to the east of "the hatch" though I'd had John Locke on the phone and he's apparently directly on top of it.

Link to comment
Share on other sites

Posted
  • Location: Beckenham, Kent, UK
  • Weather Preferences: Thunderstorms, snow, strong winds
  • Location: Beckenham, Kent, UK
44 minutes ago, Flash bang flash bang etc said:

Beat me to it

I’m headed to Tonbridge shortly. Want to be in the hatch

Yh. I’m right in the black hatched zone anyway! Hoping to get some amazing pictures of lightning over London tonight providing this all goes to plan

Link to comment
Share on other sites

Posted
  • Location: Kensington
  • Location: Kensington

Seems like most of the models see the action further east  over England  the latest icon however bucks that trend  with a westerly correction  maybe one rogue run   but it does show that it isn't pinned down just yet   some however will get a lovely firework display 

 

 

Link to comment
Share on other sites

Posted
  • Location: Benfleet, South Essex
  • Weather Preferences: Sunny and breezy with a bit of cloud, about 20C
  • Location: Benfleet, South Essex

Should hopefully be seeing signs of life soon then.

Really feels ready to blow here, and it really can’t come quick enough in my book

Link to comment
Share on other sites

Posted
  • Location: NW London
  • Weather Preferences: Convective Weather and Snow
  • Location: NW London
Just now, Thunderstruck said:

Should hopefully be seeing signs of life soon then.

Really feels ready to blow here, and it really can’t come quick enough in my book

Yep. Showers over N France now!

Link to comment
Share on other sites

Posted
  • Location: spalding, sth lincs
  • Location: spalding, sth lincs

evening all, wow, its so muggy tonight, weather station still reading 24.5c under cloudy skies, no storms forecast according to bbc and metoffice, but here is hoping we do get a storm to clear the air or lets hope the rain will cool things down.

Link to comment
Share on other sites

Posted
  • Location: Nutley, East Sussex 120m ASL
  • Location: Nutley, East Sussex 120m ASL
46 minutes ago, Flash bang flash bang etc said:

Beat me to it

I’m headed to Tonbridge shortly. Want to be in the hatch

Don’t go all the way to tonbridge I would suggest stopping at an parking place looking South on the Ashdown forest pm for exact location I’m defiantly heading out tonight as well!! 

Link to comment
Share on other sites

Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

It’s building in Northern France as the warm plume heads north and is hitting the moister air. Trigger time

Link to comment
Share on other sites

http://www.camsecure.co.uk/Camsecure2/bournmouth_pier_webcam.html sky looking out to sea from bournemouth maybe could get something later looking out for lightning later might check the brighton one as well

 

Link to comment
Share on other sites

Posted
  • Location: Bedfordshire
  • Weather Preferences: Thunderstorms, plumes, snow, severe weather
  • Location: Bedfordshire

Lightning strikes over France!!!!

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Bexhill-on-sea, East Sussex (11.8M ASL)
  • Weather Preferences: Thunderstorms, snow, and wind storms
  • Location: Bexhill-on-sea, East Sussex (11.8M ASL)

SFERICS OVER FRANCE!

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Nutley, East Sussex 120m ASL
  • Location: Nutley, East Sussex 120m ASL
2 minutes ago, chionomaniac said:

It’s building in Northern France as the warm plume heads north and is hitting the moister air. Trigger time

Chino are you going out chasing?

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
×
×
  • Create New...